Apparatus for degasifying liquids



Dec. 15, 1936. l EMANUELl 2,064,650

APPARATUS FOR'DEGASIFYING LIQUIDS Filqd oct. 25, 19:54

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IVA/evitar` His Attorney- Patented Dec. 15, 1936 Nitro stares APPARATUS FOR DEGASIFYING LIQUIDS Luigi Emanueli, Milan, Italy, assigner to Societal Italiana Pirelli, a corporation of Italy Application October 23, 1934, Serial No. 749,537

En taly April 18, 1934 3 Claims.

The present invention relates to apparatus 4for degasifying liquids, especially oil for use in oil filled cables where the presence of gas and moisture is very detrimental, and has for its object 5 the provision of an improved apparatus of high eiciency for the purpose. I

For a consideration of what I believe to be novel and my invention, attention is directed to the accompanying description and the claims appended thereto.

In my improved apparatus, the liquid to be degasied is expanded or spread several times in succession in very thin layers, each having a large surface area, by means of centrifugal force, o in a vessel subjected to vacuum and eventual heating. This is conveniently done by means of a series of elements of conical shape having their vertexes at the bottom, said elements being ixed to a rotating shaft and arranged to 4alter-v nate with a like series of xed elements also of conical shape, the vertexes of which areopen. Th liquid to be deg'asiied is introduced into the center of the first rotatable cone Where'it is spread outwardly by centrifugal force due to the rotation of the cone. On leaving the first rotating cone, the liquid is caught by the first ixed cone which, being open in the center, confor oil-filled cables, it is not possible to obtain as high a degree o f vacuum as is desired. This fact limits the degree of degasication which can be reached, as it cannot increase beyond a certain limit by increasing the number of cones employed. With the object of considerably increasing the efiiciency of the apparatus, according to the present invention, I subdivide it into two or more sections or stages placed Yone over the other, though forming only one structure, .with all of the rotating cones supported by a single rotating shaft. The sections are intercommunicating as far as the oil is concerned, that is, the oil can pass successively from one section to the next, but they are not inter-communicating as regards bearing 2 and has a guide bearing and seal 3 (Gl. 18S-2.5)

the gas which is extracted from the said sections by separate pumps creating successively higher degrees of vacuum.

In vorder to obtain this communication of the liquid between successive sections, a suitable arrangement of hydraulic tightness, such as a tube or tubes in the form of a U, is used. To prevent communication betweenlthe gaseous chambers, the passage of the rotatable axis from one section to the other is made, according to the present invention, by means of a special seal or liquid-tight device, without y stuffing box,- in which the axis is perfectly free to turn.

In Fig. l of the attached drawing is shown one way of executing the present invention, bew ing formed, for simplicity in drawing, of only two sections,.and Fig. 2 is a detail view of shaft sealing means.

The shaft i is 'mounted on a suitable step at the upper end. A pulley or other means t is used tofdrive the shaft.`

The ,container or vessel of the apparatus, vacuum-tight, is formed inseveral parts or sectionsA 5, 6 and 'I xed one on the other, the lowest 5 of which serves to collect the degasified liquid, While each one of the others contains rotatable cones 8 mounted on the shaft l and in alternation with stationary cones 'gf The stationary cones in each section are supported at their 30 edges by a cylindrical member i0. The upper member is attached to and supported by the cover l I, and the lower member by the partition l2 betweenthe two sections. The stepbearing for the shaft is supported by the partition i3, 35 the latter having suitable openings i4 to permit the liquid to flow into the chamber of the part l.

Vacuum pump l5 is connected by a pipe I6 to section 5, and vacuum pump Il by pipe i8 to section 6. The pump il creates a higher degree 40 vacuum than the pump l5. Shut-off valves i9 are provided where necessary. Liquid enters the upper section through a pipe 20 and undergoes its first degasication therein. The degasiiied liquid then flows through one or onore U-shaped 4r tubes 2l into fsection, Where, due to pump il, there is a higher degree of vacuum and Where it undergoes a more complete degasication. The

U-tube 2i, which is hydraulically tight, allowsy liquid to ow from chamber 22 of one section to 50 chamber 23 of the other but does not permit gas to pass from one chamber to the other although they have different degrees of vacuum.

As shown in Fig. 2, the separating Wall or partition I 2 between the two successive sections 55 has in its center part a cavity with a large opening at its base 24 for the passage of the shaft I. A collar is slipped over the shaft, which collar has a iiange 25 resting on the base 24. The

Y 'cavity is lled with liquid which has been degasied in the rst `section or stage. of the apparatus. While shaft I revolves, the collar 25 is more or less made to rotate with it, so forming with the shaft a sufficiently good seal for the liquid. The passage of the liquid is prevented, however, through the opening in the base 24 bythe flange 25, especially during rotation.. In this way, the rotatable axis rests only on the step bearing 2 so that a support or intermediate stuffing box is avoided.V Nevertheless, the passage of the liquid between the two sections along the axis is almost completely avoided, and the separation between the gaseous chambers of the adjoining. sections of the apparatus is also perfect. In other words a hydraulic seal is provided between the chambers of the two sections, and the liquid also serves to lubricate the relatively movable parts. Any gas which may be entrained in any oil which may leak through the seal is extracted by the pump I1.

The degasied liquid collects in the lowest section 1, until the float 26 on being raised automatically by a rise in level of the oil, interrupts, by means of a piston valve 21, the communication between the inlet pipe 28 of the liquid to be degasified and the tube 20 which introduces the liquid into the apparatus. Liquid is supplied to inlet pipe 28 to the apparatus from any suitable source.v

The degasified liquid is extracted by a pump 29 through the pipe 30 from the chamber inthe casing 1, a shut-off valve 3| being included in the pipe.

What I claimas new and desire to secure by Letters Patent of the United States is:

i 1. In an apparatus for degasifying liquids, the

combination of a vertical casing having top, bottom and side walls, a partition dividing the cas- .ing into two separate chambers, a second perrotors for discharging liquid outwardly by centrifugal force carried by the shaft and located one in each of the chambers, a set of conical stationary elements located in each of the chambers for receiving the liquid discharged by the rotors, each of said elements partly enclosing the rotors, annular members for supporting the setsV of stationary elements, one of said members being supported by the top wall of the casing and the other by the partition between the chambers, separate vacuum pumps for the rotor containing chambers, one of which produces a higher degree of vacuum than the other, a conduit'for conveying liquid to theupper chamber and delivering it on to a conical rotor located therein, a conduit and pump for removing degasified liquid from the collection chamber, and a conduit registering with. an opening in the first named partition for conveying partially degasiled liquid from one chamber to another and discharging it on to a conical rotor located therein.

2. In an apparatus for degasifying liquids, the combination of a vertically disposed vessel, a horizontal partition dividing the vessel into two chambers to form stages which operate at different sub-atmospheric pressures, a vertical shaft extending through the partition, bearings therefor, a set of conical rotors located in each chamber and mounted on the shaft and rotated thereby, a set of stationary conical elements located` in each of the chambers and extending between pairs of the vconical rotors for receiving liquid discharged by centrifugal force from one rotor and conveying it to an adjacent rotor, an annular support common to the stationary elements of each stage located within the chamber thereof and restricting the outward movement of the comprising a collar with an opening through l which the shaft loosely extends and which freely rests on the partition to permit of sidewise movement for preventing free passage of. liquid around the shaft from the upper to the lower chamber, and conduit means for supplying raw liquid to the rotor of the rst chamber.

3. In an apparatus for degasifying liquids, the combination of a vertically disposed vessel, a horizontal partition dividing the vessel into two chambers to form stages which operate at different sub-atmospheric pressures, a vertical shaft extending through the partition, bearings therefor, a set of corneal rotors located in each chamber and mounted on the shaft and rot-ated thereby, a set of stationary conical elements located in each of the chambers and extending between pairs of the conical rotors for receiving liquid discharged by centrifugal force from one rotor and conveying it to an'adjacentrotor, an annular support common to the stationary elements of each stage located within the chamber thereof vand restricting the outward movement of the liquid discharged by the rotors, a vacuum pump connected to one of the chambers for maintaining a determined sub-atmospheric pressure therein, a second pump connected to the other of the chambers for maintaining a determined pressure therein which is lower than that in the first chamber, a conduit of U-shape to form a trap which receives partially degasified liquid from the first chamber and discharging it on to the upper .of the conical rotors located within the second chamber, a hydraulic sealing means for the shaft comprising a recessed portion of the degasified liquid in the chamber at the bottom j of the vessel for controlling the passage of raw `liquid through the. conduit means, and a pump for removing degasied liquid from the last' 

